1. Field of the Invention
The present invention relates to cotton harvesting machines, and more particularly to a remotely operable motorized assembly for adjusting the vertical position of the doffer assembly of a cotton harvester relative to the picker spindles.
2. Description of the Prior Art
Conventional cotton harvesting machines include two or more harvesting units attached near the front of the machine. Each harvesting unit includes at least one vertically oriented picker rotor or drum and a corresponding doffer assembly. Each picker rotor includes a plurality of vertically spaced rows of rotatable cotton picker spindles. As the harvester moves through rows of mature cotton plants, the rotating spindles become entangled with and engage the cotton fibers removing them from the plant and winding them around the spindles. As the picker drum rotates, the spindles with cotton wound around them are brought into contact with the corresponding doffer assembly which strips the cotton from the spindles. The doffed cotton is then conveyed through and out of the harvesting machine.
The spindles of each picker rotor are typically arranged in a series of rows vertically spaced apart from each other. Each corresponding doffer unit includes a series or stack of vertically spaced doffer discs or plates with rubberized pads corresponding in number to the number of rows of spindles on the picker rotor. The doffer discs are mounted on a substantially upright rotatable shaft in spaced parallel relation to the picker rotor such that the doffer discs are intermeshed with the rows of spindles in closely spaced parallel relation. Proper operation of the harvester requires that the parallel positions of the doffer discs be maintained in order to avoid excessive rubbing the discs or pads against the spindles to minimize wear while at the same time maintaining a close enough position to insure complete doffing of the cotton from the spindles.
In most field conditions, the rubberized pads on the doffer discs must just touch the surface of the picker spindles for proper removal of harvested cotton lint from the spindles. Over time, the doffer pads are gradually worn away. Such worn pads do not efficiently remove cotton from the spindles affecting the overall operation of the harvester. Accordingly, periodic adjustment of the position of the shaft supporting the doffer discs and pads is required in order to maintain a proper spatial relationship between the spindles and the doffers for optimum operation of the harvester.
Typical adjustment of the doffer support assembly is accomplished manually either by changing the position of support elements below the doffer support shaft to change the position of the shaft such as is shown in U.S. Pat. Nos. 3,224,178 and 3,292,352; or by rotating an adjustment screw associated with the upper end of the doffer support shaft an example of which is shown in U.S. Pat. No. 5,014,502. Manual adjustment of the doffer support shaft is inefficient in that it requires shutting down the cotton harvester, opening the harvesting units, accessing the doffer adjustment mechanism and making the correct manual adjustments to the shaft to bring the doffer pads into proper spacing relative to the spindles. Not only is such manual adjustment difficult and time consuming, the same adjustment must be repeated on a plurality of doffer units (up to a dozen) at or about the same time. Any slight mis-adjustment or misalignment may result in uneven wear on the affected doffer unit thereby affecting the efficiency of the particular harvesting unit.
In response to these inefficiencies, certain automated doffer adjustment devices have been developed. The adjustment apparatus of U.S. Pat. No. 4,742,672 uses a hydraulic system associated with the upper end of the doffer support shaft to continuously adjust the position of the shaft and doffer pads relative to the spindles. However, this is a complicated and expensive design, and the hydraulic components thereof are subject to considerable maintenance problems. Another automatic doffer adjustment apparatus is disclosed in U.S. Pat. No. 4,819,415 which uses a specially threaded unit provided at the top of the doffer support shaft having an adjustment means for setting the difference between the upward and downward forces on the shaft in order to maintain the positioning of the doffer pads relative to the spindles. However, this design does not appear to have high reliability and requires trial and error adjustment.
It is therefore desirable to provide a reliable and inexpensive automatic or semiautomatic apparatus for adjusting the doffer support shafts of a cotton harvester.
The present invention overcomes the drawbacks of manual doffer support shaft adjustment while at the same time providing an automatic or semi-automatic apparatus that is more reliable and inexpensive than existing automatic doffer adjustment devices through the employment of a retrofittable remotely controlled motorized assembly for attachment to the manual adjustment screw of the doffer support shaft. The assembly of the present invention includes a remotely controlled electric gear motor designed to be operably associated with the manual adjustment screw of a doffer support shaft. The gear motor is attached to a mounting bracket in the housing above the doffer support shaft.
In one aspect of the invention, an interfacing gear is provided having a hexagonal, octagonal or other appropriately sized central opening for snug fitment over the head of the upper vertical adjustment screw for the doffer support shaft. A collar with set screw may also be provided on the gear for securing the gear to the adjustment screw. The electric gear motor is mounted to the upper housing supporting the doffer support shaft assembly and the interfacing gear is fitted over the vertical adjustment screw head such that the cogs of the interfacing gear intermesh with an outer gear of the gear motor. One or more intermediate gears are provided inside the gear box in order to facilitate an appropriate mechanical advantage and to provide the ability to make very fine adjustments to the interfacing gear on the adjustment screw. Operation of the electric motor moves the gears allowing for very fine adjustment of the upper adjustment screw relative to the upper housing allowing for very fine vertical adjustment of the doffer support shaft. Depending upon the number of intermediate or reducing gears used in the motor and their relative ratios, vertical adjustments in the range of 1/1000 inch are possible. Once operation of the motor is stopped, its internal parts are strong enough to resist any movement such that no vertical change in the position of the doffer support shaft can occur in the stopped position.
Because it is electric, the gear motor may be operated from a remote switch in the cab of the harvester while the harvester is in operation thereby avoiding the expenditure of time otherwise required for manual adjustment. A plurality of motors may be provided, one for each harvester unit of the machine. The controls may be established such that each of the motors may be operated independently, or the motors may be operated in groups (e.g. front/back, left/right, etc.), or all of the motors may be operated at the same time. The motor controls may be as simple as a single-direction pre-determined adjustment that is made to a given motor by activating a control switch. In such a situation, activating the switch causes the affected motor to operate for a predetermined (but adjustable) period of time making a pre-determined adjustment to the doffer support shaft. By way of example and for illustration purposes only, and without affecting the scope of the appended claims, a motor may be set to operate for a period of ten seconds which, according to the selected ratios of the gears of the motor, may result in a lowering of the doffer support shaft by 0.004 inch.
Alternatively, the motors may be connected to controls allowing for dual directional adjustment, with or without a pre-determined time setting. The controls may also be established such that the affected motor continues to operate as long as the user keeps the switch engaged, allowing for very slight or very significant adjustments to the corresponding doffer support shaft depending upon the length of time the motor is run.
In another aspect of the invention, the motor may be provided with an internal gear having the hexagonal, octagonal or other appropriate opening therein such that the motor assembly may be fitted directly over the vertical adjustment screw and mounted to the upper housing.
In another aspect of the invention, one or more sensors may be provided on each harvester unit in the vicinity of the spindles and doffer pads to monitor the wear on the pads. If excessive wear is detected, or if a visual gap is detected between the doffer and the spindle, the sensor(s) provide a signal to the user in the cab. The user may then cause an adjustment to be made to the affected unit until the sensor(s) indicate that the proper relationship has again been established. The sensor(s) may be adjusted in order to detect whatever amount of wear the operator desires to be reported.
In another aspect of the invention, the input from the sensors and the output to the adjustment motors may be controlled through a microprocessor or other computing unit so that adjustments may be automatically made in response to input from the sensors.
In operation, an adjustment motor assembly of the present invention is installed on each doffer assembly of the harvester by attaching the motor mount to the housing above the doffer support shaft. The gear or motor opening which corresponds with the doffer shaft adjustment screw is placed over the head of said screw. Wiring is installed to provide power to the motor using a control switch in the cab of the harvester. Depending on the aspect of the invention used, an adjustable timer may be provided with the control switch for each motor to provide power to the motor for an adjustable pre-set time, and/or the control switch may have dual polarity to allow adjustment in either direction. Activating the switch operates the motor which turns the gears and imparts rotational motion to the doffer support shaft adjustment screw. The motor mount prevents the motor itself from moving thus imparting the rotational movement directly to the screw. By turning the screw in one direction, the motor raises the doffer support shaft; by turning it in the other direction (by reversing the polarity to the motor) the motor lowers the shaft. The motor may be operated while the harvester is in operation, or when it is stopped, without the need to open or access the doffer and spindle assembly thereby saving time and avoiding potential injury to the operator.
In more advanced aspects of the invention, light or touch sensors may be deployed in the doffer assemblies to recognize when the doffer pads have become worn. When this is recognized, a signal is sent from the sensor to the cab to either alert the operator or a microprocessor that an adjustment to that doffer shaft should be made using the motorized adjustment apparatus of the present invention.
It is therefore a primary object of the present invention to provide a reliable, inexpensive remotely-controlledmotorized apparatus for adjusting the position of a doffer support shaft (and the doffer discs thereon) of a cotton harvesting machine.
It is another important object of the present invention to provide a retrofittable remotely-controlled motorized adjustment apparatus for attachment to the manual adjustment screw of a doffer support shaft of a cotton harvesting machine.
It is a further object of the present invention to provide a remotely-controlled motorized unit for adjustment of a doffer support shaft having a locking motor which prevents rotational movement unless the motor itself imparts such movement.
It is another object of the present invention to provide a remotely-controlled motorized unit for adjustment of a doffer support shaft having a plurality of gears for reducing the ratios between the motor shaft and the adjustment screw of the doffer support shaft for very fine adjustment of said screw.
It is another object of the present invention to provide a remotely-controlled motorized unit for adjustment of a doffer support shaft having an integral opening therein for fitment directly over the adjustment screw of the doffer support shaft.
It is another object of the present invention to provide a plurality of remotely-controlled motorized units for adjustment of each of the a doffer support shaft assemblies of a cotton harvesting machine.
It is another object of the present invention to provide a remotely-controlled motorized unit for adjustment of a doffer support shaft having an adjustable timer for establishing a pre-determined adjustment time for the operation of said unit.
It is another object of the present invention to provide a remotely-controlled motorized unit for adjustment of a doffer support shaft having a dual directional motor together with controls that allow operation of said motor in either direction.
It is another object of the present invention to provide a remotely-controlled motorized unit for adjustment of a doffer support shaft which includes sensors in the vicinity of the doffer support shaft which provide a signal to the operator or to a microprocessor when wear is detected on the doffer pads supported on said shaft such that an adjustment is made to the position of said shaft using said motorized unit.
Additional objects of the invention will be apparent from the detailed descriptions and the claims herein.